Traders face exchange blocks by IP: in one region the exchange is available, in another it is not. Proxies for forex solve it: the terminal connects through an address of the country where the exchange works.
Stability and low ping are critical for trading. A proxy that drops for a second can cost a trade. So choose a live verified pool, not cheap lists.
Proxies for crypto exchanges are especially relevant: many exchanges restrict access from some countries. With a proxy of the country where the exchange is allowed, you get full functionality.
For MetaTrader and other terminals SOCKS5 fits — it works with any protocol. Set the proxy in the terminal connection settings and trade without restrictions.